The objective of this research is to prepare computer-aided design (CAD) procedures for rim exhausters that (a) control contaminants from open vessels containing volatile liquids and (b) that control particle generated when powders are poured into open vessels. The transfer of powders and vapors from the open vessel to the atmosphere will be modeled analytically so that designers can predict concentrations at selected points near the source for ventilation rates and rim exhauster geometry they have chosen. The CAD does not design the rim exhauster, the designer retains that function. The CAD is merely a tool to enable designers to evaluate the effectiveness of the rim exhauster they have designed. The CAD will contain provision to include spurious room air currents, aerodynamic wakes produced by workpiece or worker and provision for a hot buoyant plume. A series of experiments will be conducted with a laboratory prototype of a rim exhauster to verify the validity of the analytical model.